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Bernie Sanders (41%) and Hillary Clinton (40%) are neck-and-neck in Iowa, according to a new survey by Quinnipiac University

Joe Biden, who is mulling a late entry into the race, collected 12% support

Washington (CNN)Bernie Sanders has drawn even with Hillary Clinton for the first time in Iowa, according to a new poll Thursday, underscoring the possibility that the once prohibitive Democratic favorite could lose both of the first two presidential contests.

Sanders edges Clinton 41% to 40% in a new survey by Quinnipiac University, overtaking the former secretary of state as she continues to be dogged by questions about her use of a private email server when she was in public office. Sanders trailed her by 21 points the last time Quinnipiac surveyed the field two months ago, and that margin has more or less held in surveys in Iowa throughout the summer -- until recently.

Vice President Joe Biden, who is mulling a late entry into the race, collected 12% support in Thursday's poll.

For Clinton, the poll will come as a sharp reminder of her 2008 race, when she also faltered in Iowa despite her once-inevitable nominee status. Clinton also trails Sanders in New Hampshire polling, the second nominating state.

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Clinton still maintains solidly double-digit leads in national polls and remains the overwhelming favorite of the Democratic establishment. But Sanders' rise has injected new drama to the Democratic race.

"He is the candidate of the Democratic left, against his own party's bosses and their prized presidential candidate," explained Quinnipiac pollster Peter A. Brown. "Sanders has seized the momentum by offering a message more in line with disproportionately liberal primary and caucus voters."

Businessman Donald Trump announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House.

"So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement.

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Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He announced he was seeking the Republican presidential nomination in a speech on March 23.

"These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant."

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Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid.

"I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.

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Hillary Clinton launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates.

"Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey."

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Sen. Bernie Sanders, an independent from Vermont who caucuses with Democrats, announced his run in an email to supporters on April 30. He has said the United States needs a "political revolution" of working-class Americans to take back control of the government from billionaires.

"This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26.

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Even if she were to ultimately lose Iowa and New Hampshire, Clinton's financial and political power could make her formidable in the states that vote next, especially in the south. But her ratings on key personality questions are giving some Democrats pause. Clinton chose to issue a formal apology this week for some of her email practices, but 30% of Democratic voters responding to the poll said they do not find her honest and trustworthy. Only 4% said the same was true of Sanders and 5% of Biden.